<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<script type="text/javascript">
			//定义变量 
			var fd=80;
			var cg;
			var c;
			//变换
			c=fd-32;
			  cg=5/9.0*c;
			  //获取前三位小数
			  num=cg.toFixed(3);
			console.log( num+'摄氏度');
		</script>
	</body>
</html>
